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  • Onsite Wastewater Treatment Facilities

    Conventional Septic System

    Onsite wastewater treatment facilities, commonly known as septic systems, are used in Pima County to dispose of household liquid waste when a home is not connected to a municipal sewer system. As these systems pose a risk for surface water and groundwater contamination, Pima County regulates the construction (including replacement), ownership transfer, and closure of septic systems. Regulations require that a septic system design conforms to the Arizona Administrative Code's Arizona State Aquifer Protection Permit (APP) Rules and the Pima County Code Title 7, and that homeowners receive permits to build and use their septic system.

    Pima County must first issue a Construction Authorization for the facility before it can be constructed or replaced. Then, after the facility passes a final field inspection, Pima County must issue a Discharge Authorization before the facility can be buried and put into use.

    An essential component of the permitting process involves performing a site investigation, which determines what type of septic system is needed for your home – Conventional or Alternative. Pima County DEQ works with Pima County Development Services Department (DSD) to control the permitting process, and have organized the permitting process into the following categories. Choose the category in the Onsite tab below and follow the instructions for permitting on that webpage.


    • Conventional Onsite Facilities:
      This type of facility is used when no site limitations have been found using the site investigation conducted under R18-9-A310. The method of disposal, detailed under code section R18-9-E302, is a septic settling tank with liquid infiltration into the soil through infiltration chambers, trenches, or beds, or a seepage pit, with flows of less than 3,000 gallons per day.
    • Alternative Onsite Facilities:
      This type of facility is used when site limitations have been found using the site investigation conducted under R18-9-A310. The methods of disposal are under code section R18-9-E303 – E323 and are highly diverse (for example: aerobic pretreatment, disinfection, and subsurface drip disposal; sewage vault-and-haul technology; composting toilet; etc.) and for flows up the 24,000 gallons per day.
    • Transfer of Property Septic Inspections:
      Forms required for use in the selling or transfer of a property that contains an active septic system.
    • System Closure or Abandonment:
      Forms required for permanently discontinuing use of septic system.
    • Liquid Waste Haulers:
      All septic tank cleaners/pumpers must apply for a PDEQ license for their business.

    How do I schedule my septic inspection?

    To schedule an inspection, call (520) 724-6970 by 4 PM the business day before you want the inspection performed, and follow the directions on the Interactive Voice Response (IVR) system.

    Notes:
    • Have the 10-digit activity number available (example: P15SS05000)
    • Select the “septic” option for inspection type
    • You must then enter the numeric portion of the activity number (example: for the above number, this would be 1505000)
    • The inspection cannot be scheduled (and the activity number won't be found in the IVR) if the inspection or re- inspection fee has not yet been paid. To see fees and make payments, please see the Fees and Payment Instructions tab of this webpage 
    • IMPORTANT: To schedule an inspection for a Remote Area (including: Ajo, Why, Lukeville, Arivaca, Sasabe, Redington, and Mt. Lemmon), please schedule the inspection at least 48 hours in advance. The system allows scheduling an inspection up the 3 business days in advance (for any longer period, contact DSD staff at (520) 724-6490).
    • Please remember to leave a voicemail for the inspector if any essential information pertaining to the inspection (gate codes, contractor contact information, etc.) needs to be shared.

    When can I expect my septic inspector?

    If you request your inspection before 4 PM using the IVR, your inspection will take place the following business day. To get an ETA, call an inspector and leave a message telling them which one of the following options you prefer:
    • Request a 2-hour ETA “window”; or
    • Request a call when they are headed to your jobsite; or
    • Request a call when the inspection is completed. Inspectors can be reached at (520) 724-7400.

    How do I cancel my inspection?

    If it is before 4 PM the day before your scheduled inspection, you can cancel your inspection using the IVR system at (520) 724-6970. If it is after 4 PM, see below.

    What if I scheduled the inspection but I’m not ready the morning of my inspection?

    You can cancel your inspection by contacting an inspector at (520) 724-7400. Leave a message if there is no answer. Cancellations must be made by 7:30 AM the day of your scheduled inspection. If an inspector arrives at your jobsite and you are not ready, the inspection will be rejected and a reinspection fee will be charged.

    When will I be charged a reinspection fee?

    After the first inspection, each subsequent site visit/inspection will be charged a reinspection fee. This includes partial inspections (Pima County 7.03.125.B.4.a.iii.c).

    How much is the reinspection fee?

    The reinspection fee is $130.00 (Pima County Code 7.03.125.B.4.a.iii.c).

    How do I pay the reinspection fee?

    The reinspection fee can be paid online (see instructions below), or by hand-delivering Cash, Check or Credit card to the DSD office at 201 N. Stone Ave., 1st Floor, Tucson, AZ 85701, or by mailing a check to the DSD office. Online payment instructions:
      1. Click the Project, Permits & Payments link of Development Service’s website
      2. Input the project’s record/permit number into the search bar in the upper right corner of the page (where it reads "Search by Address, Record #, etc) and search for it
      3. Scroll down to the Fees tab, click on any unpaid fees, and pay them by inputting your credit card information

    Can I schedule my next septic inspection before paying for the reinspection fee?

    No. The reinspection fee must be paid prior to scheduling your next septic inspection. The IVR inspection request system will not allow you to schedule the inspection until the hold is removed at the time payment is received.

    How do I view my current septic records?

    To view basic current basic septic record information and status:
      1. Click the Project, Permits & Payments link of Development Service’s website
      2. Input the project’s record/permit number into the search bar in the upper right corner of the page (where it reads "Search by Address, Record #, etc") and search for it
      3. View the basic information on the record under the Record Details tab
    To view pdf copies of the original record hardcopies (for newer records):
      1. Go to the Septic Records Portal
      2. Input the project Activity Number, Address, or Parcel number and click “Search”
    To request records that are not found in the Septic Records Portal:

    What paperwork do I need on site for the inspection?

    At the minimum, you must furnish the Watertightness Test Form and updated As-Built Plans showing any changes to the system layout that occurred after the Construction Authorization was issued. A contact phone number of the installer is also helpful to include for the inspector, in the case there of an issue.

    Who can do the watertightness test?

    Anyone (homeowner, contractor, installer, etc.) is permitted to perform the watertightness test. The person who completes the watertightness test certifies that he/she tested the installed septic tank in accordance with requirements specified in Arizona Administrative Code R18-9-A314(5)(d) and attests that the septic tank passed the watertightness test.

    How do I complete the watertightness test?

    Look at page two of a blank watertightness test sheet and view the instructions, per Arizona Administrative Code R18-9-A314(5) (d)).
    NOTE: The watertightness test must be completed BEFORE the scheduled septic inspection.

    Why does the pipe between the tank and the distribution/junction box need to be underfilled?

    Underfilling this pipe provides support when the system is backfilled and will help prevent the pipe from collapsing under the weight of the soil (Arizona Administrative Code R18-9-E302.C.1.f).

    When should I use SDR35 or equivalent pipe?

    SDR35 or equivalent pipe must be used when there is 2 feet or greater depth of cover over the piping (Arizona Administrative Code R18-9-E302.C.2.c).

    How many risers do I have put above the tank access openings?

    To comply with Arizona Administrative Code, installed risers to bring the lid within 6 inches below finished grade. This ensure that lids are easily accessible for maintenance. Make sure the risers are installed before the inspection.

    Do I leave the tank access lids open for the inspection?

    Yes. Please leave them partially or fully open so that the inspector can ensure that inlet and outlet Ts are placed properly, the filter is installed in the outlet T, and that there is sufficient water in the tank (to the operational level) from the watertightness test. Also, clean off the tank lid so the tank size is visible.

    What is the purpose of the observation ports?

    The observation ports allow you to monitor and inspect the septic system. It is possible to determine the presence/absence of standing water in the system and to assess the depth of water in the trench through the observation ports. Observation ports must allow water to flow into the bottom of the port/pipe by perforating the bottom of the pipe (only within the chamber, or, under the trench aggregate) or installing the pipe end above the bottom of the soil by a few inches. In the case of needing to pump standing water from the trench, more open access to the water allows pumpers to run a hose down the port to remove the water with a suction pump.

    What are inspection pipes?

    Inspection pipes are used in perforated pipe septic installations. They are placed every 10 feet to the depth that the trench was excavated. Inspectors remove the inspection pipes to determine the effective depth (depth under the perforated pipe) as well as the total trench depth.

    My design calls for a perforated pipe system but I want to use chambers (or vice versa). What should I do?

    The system must be redesigned. Before construction starts, have your engineer/designer submit the plan to Pima County Development Services and request a revised Construction Authorization, which entails paying the $270 re-review fee.

    My design calls for 6.25’ chambers but I can only find 4’ chambers. What should I do?

    The system must be redesigned so that the new chambers achieve the same or greater effective absorption area. Have your engineer/designer submit as-built design revisions to Pima County Development Services before scheduling the construction inspection.

    Can I alter the location of my leach fields after the original design has been approved?

    The leach field trenches can be rotated as long as they stay centered around the location of the original soil test holes and stay within all the required setbacks. If laterally shifting the trenches, they can be moved at most 20 feet from the original location, if necessary. The trenches can be moved into the reserve area only if an additional soil test hole is dug in the area (for a total of two holes), and a new reserve area is established -- this requires submitting a revised design, including the $270 re-review fee.

    What is required when installing two tanks in series?

    The baffle must be removed from the first tank. This is because the first tank will act as the inlet compartment and must be 2/3 to 3/4 of the combined tank capacity (Arizona Administrative Code R18-9-A314.1.c.ii, R18-9- A314.4.c). The inlet invert of the first tank must be at least 2 inches above the outlet invert of the second tank (Arizona Administrative Code R18-9-A314.1.f). Install the effluent filter on the outlet of the second tank.

    Why do I need to expose the capped ends of the perforated pipes?

    Expose the ends of the perforated pipes in the trenches so that inspectors can ensure the pipes are capped. It is also helpful to have them exposed to determine the trench lengths.

    How and why do I need to install inspection poles every 10 feet for a trench system?

    Inspection poles should be installed in order for inspectors to ensure that the depth of gravel matches the design plan, and is consistently along the length of the trench. Typically, ½” PVC pipe is the best material for these poles, which can be reused from project to project. The inspector marks the poles at various levels with a marker and then pulls them out during the inspection.

    Should I move the filter material and aggregate aside so the pipe can be seen during inspection?

    Yes, move the filter material and expose the perforated pipe approximately every 30 feet or at the midpoint of each trench.

    I’m installing a replacement septic system. Can I connect before the inspection?

    No. New and replacement septic systems must be inspected and approved by an inspector before they are put into use (Arizona Administrative Code R18-9-A309).

    How far apart do the trenches need to be?

    For perforated pipe installations, trenches need to be at least two times the effective depth (depth below the perforated pipe). For example, if the effective depth is 4 feet, trenches need to be at least 8 feet apart, measured sidewall to sidewall, not centerline to centerline. For chamber systems, trenches need to be at least 5 feet apart, measured sidewall to sidewall, not centerline to centerline (Arizona Administrative Code R18-9-E302.C.2.c).

    Can I backfill around the tank before the inspection?

    Yes. In the past, inspectors wanted the tanks to be exposed so they could examine the tank for leaks. Now, the watertightness test certifies that the tank is watertight so leaving the tank excavated is no longer necessary. Backfilling also presents a safer situation for inspectors who will need to get on top of the tank.

    Can I pave over my septic system?

    Paving over trenches is prohibited because it has a negative effect on the ability to treat wastewater. If any other part of the system is to be paved (i.e. the tank), an A312.G request must be submitted with the Notice of Intent to Discharge and Site Suitability checklist at the time of review (Arizona Administrative Code R18-9-E302.C.1.h).


    Onsite_Wastewater_FAQs.pdf

    View Septic Records

    To view basic current basic septic record information and status:
      1. Click the Project, Permits & Payments link of Development Service’s website
      2. Input the project’s record/permit number into the search bar in the upper right corner of the page (where it reads "Search by Address, Record #, etc") and search for it
      3. View the basic information on the record under the Record Details tab

    To view pdf copies of the original record hardcopies (for newer records):

      1. Go to the Septic Records Portal
      2. Input the project Activity Number, Address, or Parcel number and click “Search”

    To request records that are not found in the Septic Records Portal:
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    Department of Environmental Quality

    33 N. Stone Ave., Suite 700
    Tucson, AZ 85701

    Phone: (520) 724-7400
    Fax: (520) 838-7432


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